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PROFESSOR BRIAN COX: Why are we here?
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Where do we come from?
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These are the most
enduring of guestions.
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And it's an essential part
of human nature
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to want to find the answers.
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Now, we can trace our ancestry back
hundreds of thousands of years
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to the dawn of humarıkiınd.
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But in reality, our story extends
far further back in time.
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Our story starts with the beginning
of the universe.
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It began 13.7 billion years ago.
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And today it's filled with
oöver a hundred billion galaxies,
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each containing hundreds
of billions of stars.
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In this series,
I want to tell that story.
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Because ultimately,
we are part of the universe.
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So its story İis our story.
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It's a story that you couldn't tell
without something so fundamental
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that's it's impossible to imagine
the universe without it.
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It's woven into the very fabric
of the cosmos. Time.
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The relentless flow of time has driven
the evolution of the universe
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and created many extraordinary wonders.
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These wonders take us
from the very first moments
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in the life of the universe
to its eventual end.
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This is Chankillo
on the northwestern coast of Peru.
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And it's one of South America's
lesser known archaeological sites,
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but for me, it is surely
one of the most fascinating.
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Around two and a half
thousand years ago,
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a civilisation we know
almost nothing about
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built this fortified temple
in the desert.
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Its walls were once brilliant white
and covered with painted figures.
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Today, all but the smallest fragments
of the decorations are göne.
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The details of this culture
and all traces of its language are lost.
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And yet, if you stand
in the right place,
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you can still experience
the true purpose of Chankillo
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in fust the same way as you could
the day it was built.
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But to do that, you have to be here
before the sun rises.
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These towers form
an ancient solar calendar.
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Now, at different times of year,
the sunrise point
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is at a different place on the horizon.
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00:04:09,791 --> 00:04:11,293
Actually, December 21st,
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which here in the Southern Hemisphere
is the summer solstice, the longest day,
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and the sun Trises just
to the right of the rightmost tower.
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Then as the year passes,
the surı moves through the towers,
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until, on June 21st,
which is the winter solstice,
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the shortest day,
it rises just to the left
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of the leftmost tower.
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Actually, just in between that mountain
you can see in the distance
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and the leftmost tower.
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So at any time of year,
if you watch the sun rise,
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you can measure its position
and you can tell,
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within an accuracy of two or three days,
the date.
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Today's date is September the 15th,
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and so that means that the sun will rise
between the fifth and the sixth towers.
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Chankillo still works as a calendar,
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because the sun still rises
in the same place today
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as it did when these stones
were first laid down.
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Now, that is a magnificent sight,
as the sun burns through the towers.
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You can almost feel
the presence of the past here.
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I mean, imagine what
it must have been like.
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Thousands of citizens stood here
to greet the sun,
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which was almost certainly a deity,
almost certainly their god.
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What a magnificent achievement.
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I mean, it's probably one
of our earliest attempts
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to begin to measure the heavens.
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Over the millennia,
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that desire to measure
what's goling on in the sky
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has led to modern astronomy
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and the foundations
of our modern civilisation.
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I might build öone in my garden.
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(LAUGHS) I want one.
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The 13 towers that line this ridge
stand testament
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to our enduring fascination
with the clockwork of the heavens
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and to the direct connection
between our lives and the cosmos.
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The rising and setting of the sun
Pprovides an epic heartbeat
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that allows us to mark
the passage of time.
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A day on Farth is the 24 hours
it takes our planet
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to rotate once on its axis.
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Our months are based
on the 29 and a half days
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it takes the moon to wax and wane
im the night sky.
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And a year is the 365 and a guarter days
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it takes us to orbit
öonce around the sun.
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These familiar time scales
mark the passing of our lives,
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but the life of the universe
plays out on a much grander scale.
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When you look up into the night sky,
you don't just see stars,
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those tiny points of light
are a million different clocks,
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whose life spans mark out
the passage of time
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over billions or even trillions
of years.
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This film is about the greatest
expanses of time.
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The deep time that shapes the universe.
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From its fiery beginnings
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through countless generations
of stars, planets and galaxies
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to its eventual demise,
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the fate of the universe
is determined by the passage of time.
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Time scales in the cosmos
seem so unimaginabliy vast
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it's almost impossible
to relate to them.
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Yet there are places on Earth
where we can begin to encounter time
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on these universal scales.
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This is Ostional on the northern
Pacific coast of Costa Rica,
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and I've come here
to witmess a natural event
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that's been happening long before
there were arıy humans here to see it.
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And I suppose it really is a window
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into the distant past
of life on our planet.
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(INDISTINCT)
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Once the sun has dipped
below the horizon
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and the moon conspired
to make the tides just right,
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this beach is visited
by prehistoric creatures.
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Ünder the cover of darkness,
they emerge from the ocean.
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Playa Ostional is öone of the few
beaches in the world
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where large numbers of sea turtles
make their nests.
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But what makes this truly remarkable
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is the sheer length of time
scenes like this have been playing out.
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This is part of one of the oldest
life cycles on Earth.
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On nights like these
for the last hundred million years,
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turtles like this have been
hauling themselves out of the ocean
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to lay their eggs.
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It's an almost
incomprehensible time span.
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I mean, a hundred million years ago
there were dinosaurs roaming the Earth
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but the Earth itself
looked very different.
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I mean, South America
was not connected to North America.
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North America was somewhere
over close to Europe.
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Australia was connected to Antarctica.
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It really is guite wonderful
to be so close
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to such an ancient cycle of life.
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I can hear her breathing, actually.
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(BREATHING HEAVILY)
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It's a remarkable experience.
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I mean,
it really is beautiful to see that
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on öone night of many hundreds
of millions of nights
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stretching back into the past.
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And she's gone.
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To witness a moment like this
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is to open up a connection
to the deep past,
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to experience time spans far longer
than the history of our own species.
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Yet even the hundred million years
story of the turtles
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only begins to connect us
with the vast sweep of cosmic time.
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Our entire solar system is travelling
on an unimagğinabiy vast orbit,
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spinning around the centre
of our galaxy.
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Ittakes 250 million years
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to make just one circuit
of the Milky Way.
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In the entire history of the human race,
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we've travelled less than a tenth
of one percent of that orbit.
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These cycles seem eternal
and unchanging,
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but as the story of time unfolds,
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a fundamental truth is revealed.
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Nothing lasts forever.
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This is the most profound property
of time.
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And it plays out
Just as vividiy here on Farth
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aâs it does in the depths of space.
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This is the Perito Moreno Glacier
in Patagonia in Southern Argentina,
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and it's one of the hundreds of glaciers
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that sweep down the continent
from the southern Patagonian ice fields.
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And you know, if you carry on that way,
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so south, about...
I don't know about 1000 kilometres
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you get to the end of South America
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and from then on
there's nothing till the Antarctic.
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(LAUGHS) And it feels like that today.
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The glacier is such
a massive expanse of ice,
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but at first sight
just like the cycles of the heavens,
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it appears fixed and unchanging.
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(CRACKING)
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Yet seen close-up,
it's continually on the move,
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as it has been
for tens of thousands of years.
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The whole face of the glacier
is moving into the lake,
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about something like
that much every day.
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00:16:32,533 --> 00:16:37,205
And that means that well over
a guarter of a billion tons of ice
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drop off the face of the glacier
into the lake every year.
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It's about a million tons a day.
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And you can hear it happening.
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Just every now and again,
you hear this tremendous cracking sound.
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It really is like the place is alive.
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(RUMBLING)
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You know, it's guite disturbing
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when these enormous chunks
of ice fall into the lake.
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00:17:09,320 --> 00:17:14,408
Although this thing seems stable
and the movement seems glacially slow,
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actually, there can be
really violent collapses.
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It's an incredibly dynamic place to be.
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This movement of the glacier provides
an İnsight into the nature of time.
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It is simply the öordering of events
into seguences, öone step after another.
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As time passes, snow falls, ice forms,
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the glacier gradually inches
down the valley
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00:17:57,159 --> 00:18:00,705
and huge chunks of ice
fall into the lake below.
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00:18:03,040 --> 00:18:07,295
But even this simple seguvence
contains a profound idea.
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Events always happen in the same order.
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They're never jumbled up
and they never go backwards.
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00:18:33,237 --> 00:18:37,241
Now, that is something that
you would never see in reverse.
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00:18:37,325 --> 00:18:40,995
But interestingly, there's nothing
about the laws of physics
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that describe how all those
water molecules are moving around
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00:18:45,166 --> 00:18:49,420
that prevent them from all getting
together on the surface of the lake,
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jumping out of the water,
sticking together into a block of ice
189
00:18:53,424 --> 00:18:57,511
and then gluing themselves back
onto the surface of the glacier again.
190
00:18:57,595 --> 00:19:02,058
But interestingly, we do understand
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00:19:02,099 --> 00:19:05,102
why the world doesn't run in reverse.
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00:19:05,186 --> 00:19:08,564
There is a reason,
we have a scientific explanation,
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00:19:08,648 --> 00:19:11,359
and it's called the arrow of time.
194
00:19:22,078 --> 00:19:24,955
We never see waves
travelling across lakes,
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00:19:25,039 --> 00:19:29,377
coming together and bouncing
chunks of ice back onto glaciers.
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00:19:32,505 --> 00:19:35,716
We are compelled to travel
into the future.
197
00:19:36,926 --> 00:19:39,845
And that's because
the arrow of time dictates
198
00:19:39,929 --> 00:19:43,474
that as each moment passes,
things change.
199
00:19:43,557 --> 00:19:47,353
And önce these changes have happened,
they are never undone.
200
00:19:52,108 --> 00:19:57,988
Permanent change is a fundamental part
of what it means to be human.
201
00:19:58,072 --> 00:20:01,325
You know, we all age
as the years pass by.
202
00:20:01,409 --> 00:20:04,829
People are born, they live and they die.
203
00:20:05,496 --> 00:20:09,792
I suppose it's part of the joy
and tragedy of our lives.
204
00:20:09,875 --> 00:20:14,505
But out there in the universe,
those grand and epic cycles
205
00:20:14,588 --> 00:20:19,260
appear eternal and unchanging,
but that's an illusion.
206
00:20:19,343 --> 00:20:22,763
See, in the life of the universe,
jJust as in our lives,
207
00:20:22,847 --> 00:20:26,517
everything is irreversibly changing.
208
00:20:35,985 --> 00:20:38,696
By building change upon change,
209
00:20:38,779 --> 00:20:43,451
the arrow of time drives the evolutron
of the entire universe.
210
00:20:45,161 --> 00:20:47,913
And as we look out
deep in to the cosmos,
211
00:20:47,997 --> 00:20:50,332
we can see that story unfold.
212
00:20:54,128 --> 00:20:58,507
This is an image of a tiny piece
of night sky
213
00:20:58,591 --> 00:21:00,426
in the constellation of Leo.
214
00:21:00,509 --> 00:21:03,512
It's actually where the mouth
of the lion would be.
215
00:21:04,013 --> 00:21:05,973
And despite appearances,
216
00:21:06,056 --> 00:21:11,312
it is oöne of the most interesting images
taken in recent astronomical history.
217
00:21:12,354 --> 00:21:15,274
The interesting thing
is this little red blob here,
218
00:21:15,357 --> 00:21:18,694
which looks very unremarkable.
219
00:21:18,778 --> 00:21:20,571
But what that red blob is
220
00:21:20,654 --> 00:21:25,659
is the afterglow
of an enormous cosmic explosion.
221
00:21:25,868 --> 00:21:29,163
It's the death of a star
that was about, what,
222
00:21:29,246 --> 00:21:34,043
40 or even 50 times
the mass of our sun.
223
00:21:39,215 --> 00:21:43,677
Poetically named GRB 090423,
224
00:21:43,761 --> 00:21:46,764
it was öonce a Wolf-Rayet star.
225
00:21:51,685 --> 00:21:54,855
Shrouded by rapidiy swirling
clouds of gas,
226
00:21:54,939 --> 00:21:59,026
it burned 10,000 times
more brightly than our sun.
227
00:22:01,737 --> 00:22:05,950
But because it burned so brightiy,
it was extremely short-lived.
228
00:22:08,619 --> 00:22:12,414
As it died,
the giant star collapsed in on itself.
229
00:22:13,082 --> 00:22:16,502
That caused massive jets of light
and stellar materlal
230
00:22:16,585 --> 00:22:18,587
to be ejected from its poles,
231
00:22:18,671 --> 00:22:23,551
in an explosion that shone with
the light of ten million billion suns.
232
00:22:30,891 --> 00:22:34,728
And it's the afterglow
of this catastrophic explosion
233
00:22:34,812 --> 00:22:39,525
that is just visible from our planet
as a faint red dot.
234
00:22:45,489 --> 00:22:50,327
But that's not what's so interesting
about GRB 090423.
235
00:22:50,411 --> 00:22:55,040
You see, when we look up into the sky
at distant stars and galaxies,
236
00:22:55,124 --> 00:22:56,959
then we're looking back in time,
237
00:22:57,042 --> 00:23:01,463
because the light takes time
to journey from them to us.
238
00:23:01,547 --> 00:23:06,010
And the light from that red dot
has been travelling to us
239
00:23:06,093 --> 00:23:10,055
for almost the entire history
of the universe.
240
00:23:10,556 --> 00:23:12,391
You see, what we're looking at here
241
00:23:12,474 --> 00:23:17,062
is an event that happened
13 billion years ago.
242
00:23:17,146 --> 00:23:19,607
I mean, that's only
about 600 million years
243
00:23:19,690 --> 00:23:22,651
after the Big Bang,
after the universe began.
244
00:23:22,735 --> 00:23:27,781
So this is something incredibly early
in the universe's history.
245
00:23:27,865 --> 00:23:32,036
In fact,
this is the oldest single object
246
00:23:32,119 --> 00:23:34,330
that we've ever seen.
247
00:23:34,830 --> 00:23:37,917
What we're looking at here
is the explosive death
248
00:23:38,000 --> 00:23:41,503
of one of the first stars
in the universe.
249
00:23:53,724 --> 00:23:58,187
As it evolves, the universe passes
through distinct eras.
250
00:24:00,314 --> 00:24:03,859
Vast ages, whose beginnings and endings
251
00:24:03,901 --> 00:24:06,862
are marked by unigue milestones.
252
00:24:08,948 --> 00:24:12,242
The births and deaths of its wonders.
253
00:24:18,582 --> 00:24:23,462
The moment the first stars were born
is one of the most important changes
254
00:24:23,545 --> 00:24:25,839
in the evolution of the cosmos.
255
00:24:28,300 --> 00:24:31,178
It signals the end
of the Primordial Era
256
00:24:31,887 --> 00:24:36,517
and marks the beginning
of the second great age of the universe.
257
00:24:38,060 --> 00:24:40,938
The time in which we live,
258
00:24:40,980 --> 00:24:43,107
the Stelliferous Era,
259
00:24:43,190 --> 00:24:45,943
the age of the stars.
260
00:24:50,698 --> 00:24:53,701
Starlight illuminates the night sky
261
00:24:53,742 --> 00:24:57,121
and starlight illuminates our days.
262
00:24:57,204 --> 00:25:02,209
Our sun is just one of 200 billion stars
in our galaxy.
263
00:25:02,292 --> 00:25:07,172
And our galaxy is one of 100 billion
in the observable universe.
264
00:25:07,715 --> 00:25:11,802
Countless islands of countless stars.
265
00:25:24,648 --> 00:25:28,068
Although the universe
is over 13 billion years old,
266
00:25:28,152 --> 00:25:32,406
we still live close to the start
of the Stelliferous Era.
267
00:25:32,489 --> 00:25:37,703
And it's an age of astonishing
beauty and complexity in the universe.
268
00:25:41,290 --> 00:25:45,377
The cosmos is absolutely
awash with stars,
269
00:25:45,461 --> 00:25:48,547
surrounded by nebulae
and systems of planets.
270
00:25:49,131 --> 00:25:54,303
There are countless billions of worlds
that we've yet to explore.
271
00:26:00,934 --> 00:26:05,439
But the cosmos isn't static
and unchanging
272
00:26:05,522 --> 00:26:08,567
and it won't always be this way.
273
00:26:08,650 --> 00:26:12,112
Because as the arrow of time plays out,
274
00:26:12,196 --> 00:26:16,825
it produces a universe
that is as dynamic as it's beautiful.
275
00:26:24,458 --> 00:26:28,420
We've seen stars born
and we've seen stars die.
276
00:26:29,088 --> 00:26:33,258
And we know that tomorrow
won't be the same as today.
277
00:26:33,425 --> 00:26:35,761
Because the arrow of time
says the future
278
00:26:35,844 --> 00:26:38,680
will always be different from the past.
279
00:26:41,058 --> 00:26:43,268
But what drives this evolution?
280
00:26:44,061 --> 00:26:48,190
Why is there a difference
between the past and the future?
281
00:26:49,066 --> 00:26:52,069
MWhy is there an arrow of time at all?
282
00:27:13,757 --> 00:27:17,261
We all have an intuitive understanding
of the arrow of time.
283
00:27:22,391 --> 00:27:25,102
İt seems obvious to us
that things change
284
00:27:25,185 --> 00:27:27,980
and the future will be
different to the past.
285
00:27:33,861 --> 00:27:36,530
We know that because we see the effects
286
00:27:36,613 --> 00:27:39,449
of the passing years all around us.
287
00:27:49,459 --> 00:27:54,131
This is Kolmanskop, an abandoned
diamond-mining town in southern Namibia.
288
00:28:03,140 --> 00:28:06,351
Now, this entire town
was founded in 1908,
289
00:28:06,435 --> 00:28:08,729
when a worker,
who was building the railway
290
00:28:08,812 --> 00:28:12,691
from the Port of Lüderitz inland,
into the centre of Namibia,
291
00:28:12,774 --> 00:28:17,112
found a single diamond
here in this desert.
292
00:28:33,170 --> 00:28:37,841
For 40 years, this was a thriving
community of up to 1000 people,
293
00:28:37,925 --> 00:28:40,469
a place where you could
become a millionaire
294
00:28:40,594 --> 00:28:42,930
picking diamonds out of the sand.
295
00:28:47,142 --> 00:28:50,437
While the money rolled in,
they built grand houses
296
00:28:50,520 --> 00:28:53,523
and lived a champagne lifestyle
in the desert.
297
00:28:56,860 --> 00:29:00,530
But when the diamonds dried up
the town was abandoned
298
00:29:00,614 --> 00:29:04,076
and for half a century,
it's fallen into disrepair
299
00:29:04,159 --> 00:29:07,037
as it's slowly reclaimed by the sands.
300
00:29:23,553 --> 00:29:26,181
The processes at play here
at Kolmanskop
301
00:29:26,265 --> 00:29:29,059
are happening everywhere
in the universe.
302
00:29:29,935 --> 00:29:32,229
Because it isn't simply
permanent change
303
00:29:32,312 --> 00:29:34,481
that's central to the arrow of time,
304
00:29:34,940 --> 00:29:36,275
it's decay.
305
00:29:39,569 --> 00:29:42,698
But the scientific explanation
for why that is
306
00:29:43,532 --> 00:29:45,575
didn't come from attempting
to understand
307
00:29:45,659 --> 00:29:48,161
the effects of time in the universe.
308
00:29:49,788 --> 00:29:52,666
It came from trying to build
a faster train.
309
00:29:55,585 --> 00:29:57,379
Back in the 19th century,
310
00:29:57,421 --> 00:30:01,758
engineers were concerned
with the efficiency of steam engines.
311
00:30:01,883 --> 00:30:04,886
You know, how hot should the fire be?
312
00:30:04,970 --> 00:30:07,180
What substance should you boil
in the steam engine?
313
00:30:07,222 --> 00:30:09,599
Should it be water
or should it be something else?
314
00:30:09,683 --> 00:30:12,060
These were profound guestions.
315
00:30:12,102 --> 00:30:16,064
And out of those guestions
arose the science of thermodynamics.
316
00:30:16,189 --> 00:30:19,776
It's when concepts like heat
and temperature and energy
317
00:30:19,860 --> 00:30:22,863
entered the scientific vocabulary
for the first time.
318
00:30:23,447 --> 00:30:27,075
Now, along with that
deeper understanding
319
00:30:27,159 --> 00:30:31,330
emerged what is probably
the most important law of physics
320
00:30:31,413 --> 00:30:34,499
for understanding
the evolution of the universe
321
00:30:34,541 --> 00:30:36,668
and the passage of time.
322
00:30:36,752 --> 00:30:39,796
It's called the second law
of thermodynamics.
323
00:30:45,093 --> 00:30:48,764
The reason the second law
of thermodynamics was so profound
324
00:30:48,847 --> 00:30:53,393
was because at its heart
it contained a radically new concept,
325
00:30:54,561 --> 00:30:57,064
something physicists call "entropy”".
326
00:31:00,609 --> 00:31:04,529
Entropy explains why,
left to the mercy of the elemenits,
327
00:31:04,613 --> 00:31:09,201
mortar crumbles, glass shatters
and buildings collapse.
328
00:31:12,621 --> 00:31:15,916
And a good way to üunderstand how
is to think of objects
329
00:31:15,999 --> 00:31:20,629
not as single things, but as being
made up of many constituent parts,
330
00:31:21,296 --> 00:31:25,258
like the individual grains
that make up this pile of sand.
331
00:31:28,303 --> 00:31:30,180
Now, entropy is a measure
332
00:31:30,222 --> 00:31:32,682
of how many ways
I can rearrange those grains
333
00:31:32,766 --> 00:31:35,435
and still keep the sand pile the same.
334
00:31:35,519 --> 00:31:40,440
And there are trillions and trillions
and trillions of ways of doing that.
335
00:31:40,565 --> 00:31:43,193
I mean, pretty much anything
I do to this sand pile,
336
00:31:43,276 --> 00:31:46,029
if I mess the sand around
and move it around,
337
00:31:46,113 --> 00:31:48,824
then it doesn't change
the shape or the structure at all.
338
00:31:49,324 --> 00:31:51,952
So, in the language of entropy,
339
00:31:52,035 --> 00:31:54,204
this sand pile has high entropy,
340
00:31:54,329 --> 00:31:57,082
because there are many, many ways
that I can rearrange
341
00:31:57,165 --> 00:31:59,751
its constituents and not change it.
342
00:32:00,794 --> 00:32:04,506
But now let me create
some order in the universe.
343
00:32:12,055 --> 00:32:14,975
Now, there are approximately
as many sand grains
344
00:32:15,058 --> 00:32:18,770
in this sandcastle
as there are in the sand pile.
345
00:32:18,854 --> 00:32:22,941
But now, virtually anything
I do to it will mess it up,
346
00:32:23,024 --> 00:32:26,820
will remove the beautiful order
from this structure.
347
00:32:26,862 --> 00:32:30,699
And because of that,
the sandcastle has a low entropy.
348
00:32:30,782 --> 00:32:33,118
Iİt's a much more ordered state.
349
00:32:33,368 --> 00:32:36,830
So many ways
of rearranging the sand grains
350
00:32:36,913 --> 00:32:40,500
without changing the structure,
high entropy.
351
00:32:40,542 --> 00:32:43,420
Very few ways
of rearranging the sand grains
352
00:32:43,503 --> 00:32:48,717
without changing the structure,
without disordering it, low entropy.
353
00:32:57,893 --> 00:33:01,146
Now, imagine I was to leave
this castle in the desert all day,
354
00:33:01,229 --> 00:33:03,648
then it's obvious
what's going to happen.
355
00:33:03,732 --> 00:33:06,485
The desert winds
are going to blow the sand around
356
00:33:06,568 --> 00:33:10,113
and this castle
is going to disintegrate.
357
00:33:10,238 --> 00:33:12,199
It's going to become less ordered,
358
00:33:12,616 --> 00:33:14,367
it's going to fall to bits.
359
00:33:17,913 --> 00:33:21,249
But think about what's happening
on a fundamental level.
360
00:33:21,333 --> 00:33:24,920
I mean, the wind is taking
the sand off the castle
361
00:33:25,045 --> 00:33:28,882
and blowing it over there somewhere,
and making a sand pile.
362
00:33:29,007 --> 00:33:32,344
There's nothing fundamental
in the laws of physics
363
00:33:32,427 --> 00:33:36,806
that says that the wind couldn't
pick up some sand from over here,
364
00:33:36,890 --> 00:33:42,437
deposit it here and deposit it
in precisely the shape of a sandcastle.
365
00:33:43,146 --> 00:33:46,900
You know, in principle,
the wimd could spontaneously build
366
00:33:46,983 --> 00:33:49,819
a sandcastle out of a pile of sand.
367
00:34:00,664 --> 00:34:02,541
There's no reason
why that couldn't happen.
368
00:34:02,624 --> 00:34:05,752
İt's just extremely, extremely unlikely,
369
00:34:05,835 --> 00:34:09,339
because there are very few ways
of organising this sand
370
00:34:09,381 --> 00:34:11,341
so that it looks like a castle.
371
00:34:18,014 --> 00:34:20,267
It's overwhelmingly more likely
372
00:34:20,350 --> 00:34:22,602
that when the wind
blows the sand around,
373
00:34:22,686 --> 00:34:26,147
it will take the low entropy structure,
the castle,
374
00:34:26,273 --> 00:34:30,277
and turn it into a high entropy
structure, the sand pile.
375
00:34:37,701 --> 00:34:41,162
So entropy always increases.
376
00:34:41,580 --> 00:34:46,960
Why is that? Because it's overwhelmingly
more likely that it will.
377
00:34:56,386 --> 00:34:59,931
It seems incredible that a law
that says that sandcastles
378
00:35:00,015 --> 00:35:02,267
don't spontaneously form on the wind
379
00:35:03,226 --> 00:35:06,354
could solve one of the deepest
mysteries in physics.
380
00:35:09,232 --> 00:35:12,485
But by saying entropy always increases,
381
00:35:12,569 --> 00:35:16,615
the second law of thermodynamics
is able to explain
382
00:35:16,698 --> 00:35:19,534
why time only runs in öone direction.
383
00:35:35,175 --> 00:35:38,595
The second law of thermodynamics,
for me, demonstrates everything
384
00:35:38,678 --> 00:35:43,600
that is powerful and beautiful
and profound about physics.
385
00:35:43,683 --> 00:35:46,728
You see, here's a law that
entered science as a way of talking
386
00:35:46,811 --> 00:35:50,357
about how heat moves around
and the efficiency of steam engines,
387
00:35:50,899 --> 00:35:54,527
but it ended up being able to explain
388
00:35:54,611 --> 00:35:57,989
one of the great mysteries
in the history of science.
389
00:35:58,114 --> 00:36:01,660
Why is there a difference
between the past anıd the future?
390
00:36:02,285 --> 00:36:04,204
You see, the second law says
391
00:36:04,287 --> 00:36:08,041
that everything tends
from order to disorder.
392
00:36:08,583 --> 00:36:12,879
That means that there is a difference
between the past and the future.
393
00:36:12,962 --> 00:36:15,465
In the past,
the universe was more ordered,
394
00:36:15,548 --> 00:36:19,052
and in the future,
the universe will be less ordered.
395
00:36:19,469 --> 00:36:22,806
And that means that there's a direction
to the passage of time.
396
00:36:22,889 --> 00:36:25,558
So the second law of thermodynamics
397
00:36:25,642 --> 00:36:27,727
has introduced the concept
398
00:36:27,811 --> 00:36:31,022
of an arrow of time into science.
399
00:36:38,988 --> 00:36:42,659
The arrow of time has been
playing out in Kolmanskop
400
00:36:42,701 --> 00:36:45,912
since the mining facility
Was abandoned in 1954.
401
00:36:48,707 --> 00:36:51,459
But in the universe,
it's been playing out
402
00:36:51,501 --> 00:36:53,753
for almost 14 billion years,
403
00:36:55,004 --> 00:36:57,632
and it will have profound conseguences.
404
00:37:05,056 --> 00:37:08,727
Because it means
stars cannot shine forever,
405
00:37:09,686 --> 00:37:13,523
including the star at the centre
of our solar system.
406
00:37:16,401 --> 00:37:20,989
At the end of its life, the sun
won't simply fade away to nothing.
407
00:37:23,950 --> 00:37:27,871
As it begins to run out of fuel,
its core will collapse,
408
00:37:28,329 --> 00:37:32,751
and the extra heat this generates
Will cause its outer layers to expand.
409
00:37:39,674 --> 00:37:41,843
In around a billion years' time,
410
00:37:41,926 --> 00:37:46,389
this will have a catastrophic effect
on our fragile world.
411
00:37:53,062 --> 00:37:56,316
Gradually, the Farth
will become hotter and hotter.
412
00:37:56,399 --> 00:38:00,695
So there will be one
last perfect day on Earth,
413
00:38:00,779 --> 00:38:05,784
but eventually the existence of all life
on this planet will become impossible.
414
00:38:10,371 --> 00:38:12,624
Long after life has disappeared,
415
00:38:12,707 --> 00:38:16,961
the sun will have grown so much,
it will fill the entire horizon.
416
00:38:23,843 --> 00:38:28,139
It will have become a red giant,
the last phase of its life.
417
00:38:38,316 --> 00:38:40,777
Our planet might not
survive to this pornt,
418
00:38:41,277 --> 00:38:45,573
but if it does, little more
than a scorched and barren rock
419
00:38:45,782 --> 00:38:49,744
will remain to witness
the final death throes of our star.
420
00:38:50,537 --> 00:38:52,121
(RUMBLING)
421
00:39:00,672 --> 00:39:05,468
In six billion years,
our sun will explode,
422
00:39:05,552 --> 00:39:08,513
throwing vast amounts of gas and dust
423
00:39:08,596 --> 00:39:11,432
out into space
to form a gigantic nebula.
424
00:39:18,982 --> 00:39:23,570
And at its heart will be
a faintly glowing ember,
425
00:39:23,695 --> 00:39:27,156
all that remains
of our once-magnificent sun.
426
00:39:27,240 --> 00:39:29,868
It will be smaller
than the size of the Earth,
427
00:39:29,951 --> 00:39:34,581
less than a millionth of its current
volume and a fraction of its brightness.
428
00:39:35,290 --> 00:39:38,001
Our sun will have become a white dwarf.
429
00:39:47,552 --> 00:39:52,015
With no fuel left to burn,
a white dwarf's faint glow
430
00:39:52,098 --> 00:39:56,311
comes from the last residual heat
from its extinguished furnace.
431
00:39:59,105 --> 00:40:01,065
The sun is now dead,
432
00:40:01,441 --> 00:40:03,610
its remarns slowly cooling
433
00:40:03,693 --> 00:40:06,613
in the freezing temperatures
of deep space.
434
00:40:10,700 --> 00:40:13,119
Looking at it from where
the Farth is now,
435
00:40:13,202 --> 00:40:15,955
it would only generate
the same amount of light
436
00:40:16,039 --> 00:40:18,708
as the full moon on a clear night.
437
00:40:24,005 --> 00:40:28,217
The fate of the sun
is the same as for all stars.
438
00:40:28,259 --> 00:40:31,471
One day, they must all eventually die
439
00:40:31,554 --> 00:40:35,099
and the cosmos will be plunged
into eternal night.
440
00:40:35,767 --> 00:40:38,519
And this is the most
profound conseguence
441
00:40:38,603 --> 00:40:40,188
of the arrow of time.
442
00:40:40,271 --> 00:40:43,399
Because this structured
universe that we inhabit
443
00:40:43,483 --> 00:40:47,403
and all its wonders, the stars
and the planets and the galaxies,
444
00:40:47,779 --> 00:40:50,114
carınot last forever.
445
00:40:50,198 --> 00:40:54,369
The cosmos will eventually fade and die.
446
00:40:58,831 --> 00:41:02,126
First will come the end
of the Stelliferocus Era,
447
00:41:02,210 --> 00:41:04,712
the end of the age of starliğht.
448
00:41:08,800 --> 00:41:11,552
The largest stars
are the first to disappear,
449
00:41:11,636 --> 00:41:14,555
vrolentiy collapsing into black holes,
450
00:41:14,639 --> 00:41:17,350
Just a few million years
after their formation.
451
00:41:20,228 --> 00:41:24,565
But long after they're göne,
Just one iype of star will remailn.
452
00:41:28,569 --> 00:41:33,908
This is a picture of the nearest star
to our solar system, Proxima Centauri.
453
00:41:33,992 --> 00:41:37,829
Now, it's only 4.2 light years away,
but the reason it doesn't stand out
454
00:41:37,912 --> 00:41:40,707
against the much more distant
stars in this photograph
455
00:41:41,082 --> 00:41:44,252
is that Proxima Centauri
is incredibly tiny.
456
00:41:44,711 --> 00:41:47,380
It's the kind of star
known as a red dwarf star,
457
00:41:47,463 --> 00:41:51,175
and it's only about 11 to 12 percent
the mass of our sun.
458
00:41:51,634 --> 00:41:57,181
But to our eyes, İt would appear
to shine 18,000 times less brightly.
459
00:41:59,809 --> 00:42:02,770
But red dwarves do have one advantage
460
00:42:02,854 --> 00:42:06,774
over their much more luminous
and magnificent stellar brethren.
461
00:42:06,858 --> 00:42:09,569
And that's because they're so small,
462
00:42:09,736 --> 00:42:13,072
they burn their nuclear fuel
incredibly slowly,
463
00:42:13,156 --> 00:42:16,743
so they have life spans
of trillions of years.
464
00:42:17,160 --> 00:42:20,663
And that means that stars
like Proxima Centauri
465
00:42:20,747 --> 00:42:24,375
will be the last living stars
in the universe.
466
00:42:30,089 --> 00:42:34,093
If we survive into the far
future of the universe,
467
00:42:34,177 --> 00:42:37,638
then it's possible to imagine
our distant descendents
468
00:42:37,722 --> 00:42:41,309
building their civilisation
around red dwarves,
469
00:42:41,392 --> 00:42:47,482
to capture the energy
from those last fading embers of stars.
470
00:42:48,024 --> 00:42:52,028
Just as our ancestors
crowded around campfires
471
00:42:52,111 --> 00:42:55,573
for warmth on cold winters' nights.
472
00:43:13,966 --> 00:43:17,720
The reason why Proxima Centauri
burns so slowly
473
00:43:17,804 --> 00:43:20,890
is because its small size
and low gravity
474
00:43:20,973 --> 00:43:24,769
meanı its core is under much
lower pressure than larger stars.
475
00:43:26,437 --> 00:43:30,233
This also means that its interior
is constantly churning,
476
00:43:30,316 --> 00:43:33,361
whipping up the surface
into a fiery turmoll.
477
00:43:36,489 --> 00:43:40,034
Explosive solar flares
occur almost continually,
478
00:43:40,118 --> 00:43:42,703
even though it burms so dimly.
479
00:43:44,789 --> 00:43:48,543
But Proxima Centauri
will eventually die.
480
00:43:49,210 --> 00:43:53,047
And like our sun,
it too will become a white dwarf.
481
00:43:54,006 --> 00:43:56,300
As the age of starlight ends,
482
00:43:56,342 --> 00:44:00,763
all but the dimmest flicker
of light in the universe will go out.
483
00:44:01,806 --> 00:44:06,269
The faint glow of white dwarves
will provide the only illumination
484
00:44:07,019 --> 00:44:13,067
in a dark and empty vord littered
with dead stars and black holes.
485
00:44:15,403 --> 00:44:20,366
By this point, the universe
will be 100 trillion years old.
486
00:44:24,287 --> 00:44:28,666
And yet, even now,
the vast mafjority of its lifespan
487
00:44:28,749 --> 00:44:30,459
still lies ahead of it.
488
00:44:47,393 --> 00:44:49,478
There are few places on Earth
489
00:44:49,562 --> 00:44:53,608
where you can get an inkling
of what the far future has in store.
490
00:45:06,913 --> 00:45:09,498
Well, this is Namibia's Skeleton Coast,
491
00:45:09,540 --> 00:45:13,669
where the cold waters of the
South Atlantic meet the Namib Desert.
492
00:45:13,753 --> 00:45:17,006
And it is one of the most
inhospitable places on Earth.
493
00:45:17,089 --> 00:45:18,799
I mean, back in the 17th century,
494
00:45:18,883 --> 00:45:20,801
Portuguese sailors
used to call this place
495
00:45:20,885 --> 00:45:25,139
"the gates to hell",
because this dense fog that you see
496
00:45:25,181 --> 00:45:28,100
pretty much every morning
along this coast,
497
00:45:28,184 --> 00:45:32,897
coupled with the constantly
shifting shape of the sandbanks
498
00:45:32,980 --> 00:45:34,941
meant that over the years,
499
00:45:35,024 --> 00:45:38,819
literally thousands of ships
were wrecked along this coastline.
500
00:45:43,950 --> 00:45:47,286
And even if you made it to shore,
that wasn't the end of your problems,
501
00:45:47,370 --> 00:45:49,580
because the currents are so strong here
502
00:45:49,664 --> 00:45:53,125
that there is no way
of rowing back out to sea.
503
00:45:53,209 --> 00:45:56,629
And if you look that way,
there's just hundreds of miles
504
00:45:56,712 --> 00:45:58,506
of inhospitable desert.
505
00:46:01,175 --> 00:46:05,304
So, it genuinely
was a place of no return.
506
00:46:05,388 --> 00:46:09,892
If you were shipwrecked here,
this was the end of your universe.
507
00:46:21,112 --> 00:46:23,197
This is the Eduard Bohlen.
508
00:46:23,656 --> 00:46:25,700
She was öonce an öcean-gorng steamer,
509
00:46:25,783 --> 00:46:29,078
ferrying passengers and cargo
between here and Furope.
510
00:46:33,916 --> 00:46:38,212
On the 5th of September, 1909,
she ran aground in thick fog.
511
00:46:44,343 --> 00:46:47,847
Yek, like all the vessels
wrecked along this shoreline,
512
00:46:47,930 --> 00:46:50,683
the time it takes her
to decay to nothing
513
00:46:50,766 --> 00:46:53,644
will be far longer than her time at sea.
514
00:46:58,941 --> 00:47:01,235
And in the far future of the cosmos,
515
00:47:01,360 --> 00:47:04,488
a similar destiny awaits
the remaining white dwarves.
516
00:47:11,162 --> 00:47:15,291
A black dwarf will be
the final fate of those last stars,
517
00:47:15,374 --> 00:47:17,877
white dwarves that have become so cold
518
00:47:17,960 --> 00:47:21,005
that they barely emit
any more heat or light.
519
00:47:25,176 --> 00:47:29,180
Black dwarves are dark,
dense, decaying balls
520
00:47:29,263 --> 00:47:31,015
of degenerate matter,
521
00:47:31,724 --> 00:47:34,268
little more than the ashes of stars.
522
00:47:36,103 --> 00:47:39,732
Their constituent atoms
are so severely crushed
523
00:47:39,815 --> 00:47:43,861
that black dwarves are
a million times denser than our sun.
524
00:47:45,404 --> 00:47:50,826
Stars take so long to reach this point
that after nearly 14 billion years,
525
00:47:50,910 --> 00:47:55,247
we believe there are currentiy
no black dwarves in the universe.
526
00:47:56,082 --> 00:47:58,000
But despite never seeing one,
527
00:47:58,084 --> 00:48:00,711
we can still predict
how they will end their days.
528
00:48:02,213 --> 00:48:06,050
Just as the iron that makes up this ship
will eventually rust
529
00:48:06,133 --> 00:48:09,345
and be carried away by the desert winds,
530
00:48:09,512 --> 00:48:12,723
so we thirik that the matter
inside black dwarves,
531
00:48:12,848 --> 00:48:15,559
the last matter in the universe,
532
00:48:15,768 --> 00:48:19,897
will eventually evaporate away
and be carried off
533
00:48:19,980 --> 00:48:25,820
into the void as radiation,
leaving absolutely nothing behind.
534
00:48:35,329 --> 00:48:37,540
With the black dwarves gone,
535
00:48:37,623 --> 00:48:40,543
there won't be a single atom
of matter left.
536
00:48:43,003 --> 00:48:46,257
All that will remain
of our önce-rich cosmos
537
00:48:46,340 --> 00:48:49,593
will be particles of light
and black holes.
538
00:48:56,600 --> 00:48:59,854
After an unimaginable length of time,
539
00:48:59,937 --> 00:49:02,940
even the black holes
will have evaporated
540
00:49:02,982 --> 00:49:06,652
and the universe will be
nothing but a sea
541
00:49:06,735 --> 00:49:10,739
of photons gradually tending
towards the same temperature,
542
00:49:10,906 --> 00:49:15,369
as the expansion of the universe
cools them towards absolute zero.
543
00:49:23,919 --> 00:49:26,380
And when I say
unimaginable period of time,
544
00:49:26,422 --> 00:49:27,506
I really mean it.
545
00:49:27,590 --> 00:49:30,801
It's 10,000 trillion
trillion trillion trillion
546
00:49:30,885 --> 00:49:34,263
trillion trillion trillion
trillion years.
547
00:49:34,847 --> 00:49:36,432
Now, how big is that number?
548
00:49:36,515 --> 00:49:40,227
Well, if I were to start
counting with a single atom
549
00:49:40,311 --> 00:49:44,023
representing one year,
then there wouldn't be enough atoms
550
00:49:44,106 --> 00:49:48,819
in the entire universe
to get anywhere near that number.
551
00:49:55,493 --> 00:49:59,205
Once the very last remnants
of the very last stars
552
00:49:59,288 --> 00:50:01,665
have finally decayed away to nothing
553
00:50:01,749 --> 00:50:05,044
and everything reaches
the same temperature,
554
00:50:05,127 --> 00:50:09,215
the story of the universe
finally comes to an end.
555
00:50:12,927 --> 00:50:15,054
For the first time in its life,
556
00:50:15,137 --> 00:50:18,390
the universe will be permanent
and unchanging.
557
00:50:19,433 --> 00:50:22,269
Entropy finally stops increasing,
558
00:50:22,353 --> 00:50:25,731
because the cosmos
carınot get any more disordered.
559
00:50:26,524 --> 00:50:30,069
Nothing happens
and it keeps not happening,
560
00:50:30,945 --> 00:50:32,279
forever.
561
00:50:36,700 --> 00:50:39,912
It's what's known as the heat death
of the universe,
562
00:50:39,995 --> 00:50:42,331
an era when the cosmos will remain
563
00:50:42,414 --> 00:50:46,585
vast and cold and desolate
for the rest of time.
564
00:50:47,419 --> 00:50:49,672
And that's because
there is no difference
565
00:50:49,755 --> 00:50:52,466
between the past,
the present and the future.
566
00:50:52,550 --> 00:50:55,261
There's no way
of measuring the passage of time,
567
00:50:55,344 --> 00:50:58,639
because nothing in the cosmos changes.
568
00:50:59,390 --> 00:51:03,310
The arrow of time
has simply ceased to exist.
569
00:51:14,029 --> 00:51:17,366
İt's an inescapable
fact of the universe,
570
00:51:17,449 --> 00:51:20,995
written into the fundamental
laws of physics.
571
00:51:21,078 --> 00:51:23,872
The entire cosmos will die.
572
00:51:28,294 --> 00:51:33,465
Every single öone
of the 200 billion stars in our galaxy
573
00:51:33,549 --> 00:51:35,009
will go out.
574
00:51:37,052 --> 00:51:39,138
And just as the death of the sun
575
00:51:39,179 --> 00:51:41,640
means the end of life on our planet,
576
00:51:41,724 --> 00:51:44,059
so the death of every star
577
00:51:44,143 --> 00:51:48,314
will extingursh any possibility
of life in the universe.
578
00:51:52,276 --> 00:51:54,945
The fact that the sun will die,
579
00:51:55,029 --> 00:51:58,866
and it will incinerate the Earth
and obliterate all life
580
00:51:58,949 --> 00:52:03,454
on our planet in the process,
might sound a bit depressing to you.
581
00:52:03,871 --> 00:52:05,331
You might legitimately ask,
582
00:52:05,414 --> 00:52:08,792
"Well, surely you could build
a universe in a different way,
583
00:52:08,876 --> 00:52:12,379
"surely you could build it
so it didn't have to descend
584
00:52:12,421 --> 00:52:14,173
"from order into chaos?"
585
00:52:14,923 --> 00:52:19,386
Well, the answer is, "No, you couldn't,
if you wanted life to exist in it."
586
00:52:25,225 --> 00:52:28,270
The arrow of time,
the seguence of changes
587
00:52:28,354 --> 00:52:31,357
that slowly leads
the universe to its death,
588
00:52:31,440 --> 00:52:33,817
is the very same thing that creates
589
00:52:33,901 --> 00:52:36,737
the conditions for life
in the first place.
590
00:52:41,033 --> 00:52:43,452
Because it takes time
for matter to form
591
00:52:44,078 --> 00:52:46,205
and it takes time for gravity
592
00:52:46,288 --> 00:52:49,249
to pull it together
into stars and planets.
593
00:52:54,254 --> 00:52:57,091
The arrow of time
creates a bright window
594
00:52:57,174 --> 00:53:01,512
in the universe's adolescence,
during which life is possible.
595
00:53:08,894 --> 00:53:12,022
But it's a window
that doesn't stay open for long.
596
00:53:15,484 --> 00:53:18,987
As a fraction
of the life span of the universe,
597
00:53:19,071 --> 00:53:21,115
as measured from its beginning
598
00:53:21,198 --> 00:53:24,076
to the evaporation
of the last black hole,
599
00:53:24,159 --> 00:53:27,579
life as we know it is only possible
600
00:53:27,621 --> 00:53:31,083
for one thousandth of a billion
billion billionth,
601
00:53:31,166 --> 00:53:35,796
billion billion billionth,
billion billion billionth of a percent.
602
00:53:38,841 --> 00:53:40,801
And that's why, for me,
603
00:53:40,884 --> 00:53:43,887
the most astonishing wonder
of the universe
604
00:53:43,971 --> 00:53:47,099
isn'ta star or a planet or a galaxy.
605
00:53:48,475 --> 00:53:52,563
Itisn'tathing at all.
İt's an instant in time.
606
00:53:53,814 --> 00:53:56,150
And that time is now.
607
00:54:04,199 --> 00:54:07,953
Humans have walked the Farth
for just the smallest fraction
608
00:54:08,078 --> 00:54:11,415
of that briefest of moments
in deep time.
609
00:54:14,334 --> 00:54:17,463
But in our 200,000 years on this planet,
610
00:54:17,546 --> 00:54:19,840
we've made remarkable progress.
611
00:54:22,676 --> 00:54:25,679
İt was only
two and a half thousand years ago
612
00:54:25,763 --> 00:54:28,557
that we believed that the sun was a god
613
00:54:28,640 --> 00:54:31,351
and measured its orbit
with stone towers
614
00:54:31,435 --> 00:54:33,979
built on the top of a hill.
615
00:54:35,731 --> 00:54:40,611
Today, the language of curiosity
is not sun gods but science.
616
00:54:40,903 --> 00:54:44,031
And we have observatories
that are almost infinitely
617
00:54:44,114 --> 00:54:46,450
more sophisticated than the 13 towers,
618
00:54:46,533 --> 00:54:49,495
that can gaze out
deep into the universe.
619
00:54:53,248 --> 00:54:56,168
And perhaps even more remarkably,
620
00:54:56,251 --> 00:54:58,253
through theoretical physics
and mathematics,
621
00:54:58,337 --> 00:55:03,592
we can calculate what the universe
will look like in the distant future
622
00:55:03,926 --> 00:55:08,347
and we can even make
concrete predictions about its end.
623
00:55:15,979 --> 00:55:20,943
And I believe it's only by continuing
our exploration of the cosmos
624
00:55:21,026 --> 00:55:23,570
and the laws of nature that gövern it
625
00:55:23,654 --> 00:55:26,448
that we can truly understand ourselves
626
00:55:26,532 --> 00:55:30,160
and our place
in this universe of wonders.
627
00:55:34,373 --> 00:55:38,919
And that's what we've done
in our brief moment on planet Farth.
628
00:55:42,756 --> 00:55:46,134
In 1977, a space probe called Voyager 7
629
00:55:46,218 --> 00:55:49,513
was launched on a grand tour
of the solar system.
630
00:55:50,514 --> 00:55:55,185
And it visited the great
gas-giant planets Jupiter and Saturn
631
00:55:55,269 --> 00:55:57,521
and made some wonderful discoveries
632
00:55:57,604 --> 00:56:01,024
before heading off
towards interstellar space.
633
00:56:03,318 --> 00:56:07,698
13 years later,
after its mission was almost over,
634
00:56:07,739 --> 00:56:11,869
it turned around
and took one last picture
635
00:56:11,952 --> 00:56:13,745
of its home solar system.
636
00:56:14,162 --> 00:56:16,039
And this is that picture.
637
00:56:18,125 --> 00:56:20,794
And the beautiful thing
about this picture
638
00:56:20,919 --> 00:56:24,590
is this single pixel of light
639
00:56:25,382 --> 00:56:27,759
suspended against
the blackness of space.
640
00:56:27,843 --> 00:56:32,180
Because that pixel,
that point, is planet Earth,
641
00:56:32,598 --> 00:56:35,267
the most distant picture
of our planet ever taken
642
00:56:35,350 --> 00:56:38,228
at six billion kilometres away.
643
00:56:47,613 --> 00:56:52,075
And whilst 1 suppose
it has very limited scientific value,
644
00:56:52,159 --> 00:56:54,786
for me, this tiny pornt of light
645
00:56:54,870 --> 00:56:58,248
is the most powerful
and profound demonstration
646
00:56:58,373 --> 00:57:01,335
of perhaps the most human of guüalities,
647
00:57:02,628 --> 00:57:04,963
our unigue ability to reflect
648
00:57:05,047 --> 00:57:08,842
on the universe's existence
and our place within it.
649
00:57:13,972 --> 00:57:16,975
Just as we, and all life on Earth,
650
00:57:17,059 --> 00:57:21,313
stand on this tiny speck
adrift in infinite space,
651
00:57:21,980 --> 00:57:25,317
so life in the universe will only exist
652
00:57:25,400 --> 00:57:30,155
for a fleeting, bright instant in time.
653
00:57:30,697 --> 00:57:35,327
Because life, just like the stars
and the planets and the galaxies,
654
00:57:35,410 --> 00:57:40,958
is just a temporary structure
on the lomg road from order to disorder.
655
00:57:50,467 --> 00:57:52,260
But that doesn't make us insignificant,
656
00:57:52,302 --> 00:57:55,013
because we are the cosmos
made conscious.
657
00:57:55,514 --> 00:58:00,352
Life is the means by which
the universe understands itself.
658
00:58:02,896 --> 00:58:06,858
And for me, our true significance
lies in our ability
659
00:58:07,651 --> 00:58:12,906
and our desire to understand
and explore this beautiful universe.
660
00:58:17,285 --> 00:58:20,956
(WE HAVE ALL THE TIME IN THE WORLD
BY LOUIS ARMSTRONG PLAYING)
57389
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